How can I reset the color palette for Windows 7?

After setting up the OS, I changed some of the system colors through the links “Personalization -> Window Colors -> Advanced Appearance” to provide an application window with Black background and White text arrangement, instead of the normally inverted options, to enable me to view the screen without eye strain, as I am a visually challenged person.

But in that process the background and font colors of several other controls got changed, without my knowledge or intention, and leading to unreadable texts – e-g: The options in a Drop-down List, Labels on control buttons (“OK”, “CLOSE” etc.). As these seem to change randomly, without my being able to identify what changes are made, and I am unable to change these, even by reverting back to the normal colors for the application windows, I am forced to work with quite a few unreadable parts in my window areas, causing me extreme difficulty.

Now I would like to know the relations between the various window system colors and how to make the desired changes for the windows through the above mentioned Personalization link, without the colors of the other controls getting changed arbitrarily.

I would be extremely grateful to anybody who can direct me appropriately.